I go out to thrift stores, buy CDs and I make a little boat to ship CDs in. I would hope someone just send me a boat back with CDs I'd listen to. To make sure of it, every CD I ship out, has a notecard written about what genre of music I like, what artists I particularly like, what genres I don't like and what artists I don't wish to hear.
This is how I make my trade. I'm a real pirate, arrrr.